HELP ASAP CAR OVERHEATING(IVE SEARCHED)

94gtslow

Founding Member
Jan 26, 2002
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Temple,Texas
well I have a 180 stat, my low speeed fan comes on when i turn the ac on, but if i just let it run, it wont come on, the high speed will only come on , and it does not come on until the A on the guage which is way too hot.


so the low speed only comes on with the a/c, when it is supposed to come on automaticly.How do i get it to turn on like its supposed to?

Whats the deal?
 
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usually it would kick on at the R on the guage. Now it does not kick on until it is almost on the A, and that is when the high kicks on.

when u turn the A/C on the fan comes on.

but it wont come on itself, like it used to. It usest to come on at the R and turn off at the O, And stay coll now it does not come on units the A, or if u turn the A/C on.

Whats the deal?
 
94SC50 said:
It could be the ECT, but you can add a manual fan switch. My fan doesn't kick on until 210. Your gauge is not that accurate either if you have a stock one.
right on.
also are you sure the system is topped up. has the stat been done lately? system opened up for any reason? could have an air pocket in there, if so.

sure the rad cap is holding pressure? if the ECT is cheap for you guys, i might swap it when i put my new gauge in (hint hint). :)

good luck.
 
I had the same problem with mine it cost me two sets of headgaskets. I belive the problem is in the relay in the box behing your cooling resevoire it has two relays in it. What I did was wire my high speed fan directly with a relay to my ignition.
 
I think we have a temperature sending unit that controls the fan. Don't know for sure though. Someone correct me if I am wrong.

The ACT=IAT = intake air temp. sensor. It has absolutely nothing to do with the cooling system.

The ECT is $15 from autozone I think. It tells the computer the temperature of the engine coolant and uses that to calculate a/f ratio & timing.

I don't know what role the ECT plays in the cooling system, so I wouldn't arbitrarily replace it.

The thermostat is cheap & easy to replace. Start with that. Next, check the pressure in the radiator hoses. If they aren't very hard to compress, your water pump "may" be bad. But the pumps for our cars aren't cheap like the foxes.
Scott
 
There are two temperature sensors on our 'stangs. The Coolant Temperature Sensor senses the temp of the coolant coming into the engine, and that value is sent to the computer. The other is the Coolant Temperature Sending Unit, and it senses the temp of the coolant exiting the engine and sends it to the temp guage in the dash. The sensors are exclusive - the computer only reads the CTS, and the guage only reports the CTSU. You could be having trouble with one or both of the guages.

Here's a link to both sensors:
http://secure.50resto.com/category.cfm?SID=1&Category_ID=586

I was having a nasty overheating problem, much like what you described. My mechanic swore that my CTSU was bad, so the guage was falsely reporting an overheating problem. I got to the "A" several times, before I finally said enough, and made the mechanic check the rest of the system. :chair: Turns out my CTS was bad - it was reporting temp values all over the place, from "cold" to "overheating" to "normal", etc. The computer didn't know what the temperature was, so it never turned the fan on. So, I WAS actually close to overheating! :fuss:

I would think that an OBD I code reader would report the coolant temperature, so you may want to try there.

If you do replace one or both, I'd stick with Motorcraft. Most of the aftermarker sensors are made of plastic, but the Motorcraft ones are made of metal - brass, I think. The metal conducts the heat better, and it lasts longer.
 
Well i noticed that when u drive around and it gets hot, then I tried to see if ther was pressure in the system after a while, and there was no pressure on the radiator cap, so i guess the cap was bad, so i replaced that, and the etc sensor.


It still runs warm R-M on guage. I drive it ez and dont use the A/C, if i use the A/C it gets even hotter. The fan does kick on till about the R on guage.
The radiator was cleaned washed out and powerwashed to get all bugs out of it a while back.

I noticed that when u kill the car and the fan winds down, it kind of makes a little noise.


Im running our of ideas.


My timing is at 14 and fp 30 vacum on, may my fp is too low?